Contactless microstrip to waveguide transition

Abstract

A microstrip to waveguide transition comprising a waveguide module and a section of printed circuit board (PCB). The waveguide module comprises a waveguide aperture and a repetitive structure, the waveguide aperture being arranged extending through the module for attaching a waveguide to an external side of the module, the repetitive structure comprising a plurality of protruding elements arranged to surround the waveguide aperture on an internal side of the module and to define a passage into the waveguide aperture on the internal side, wherein the repetitive structure is configured to attenuate electromagnetic signal propagation in a frequency band past the repetitive structure while allowing propagation via the passage, the transition further comprising a PCB with a patch antenna connected to a transmission line and arranged to face the passage into the waveguide aperture.

The invention claimed is: 
     
       1. A microstrip to waveguide transition comprising:
 a waveguide module; and 
 a printed circuit board (PCB), 
 wherein the module is arranged to interface with the PCB, the PCB comprising a patch antenna and a ground plane, the module comprising a waveguide aperture and a repetitive structure, the waveguide aperture arranged extending through the module for attaching a waveguide to an external side of the waveguide module, the repetitive structure comprising a plurality of protruding metal or metallized elements arranged to surround the waveguide aperture on an internal side of the module and to define a passage into the waveguide aperture on the internal side, 
 wherein the repetitive structure is configured to attenuate electromagnetic signal propagation in a frequency band past the repetitive structure while allowing propagation via the passage, 
 wherein the repetitive structure and ground plane constitute a gap waveguide structure, and 
 wherein the repetitive structure is arranged at a distance from the ground plane, where the distance is smaller than a quarter of an operation wavelength of the waveguide module. 
 
     
     
       2. The microstrip to waveguide transition according to  claim 1 , wherein the repetitive structure is a pin structure comprising conducting pins arranged periodically protruding from a conducting plane comprised in the waveguide module. 
     
     
       3. The microstrip to waveguide transition according to  claim 1 , wherein the waveguide module further comprises a waveguide flange extending in a plane perpendicular to the waveguide aperture, wherein the repetitive structure is integrally arranged with the waveguide flange. 
     
     
       4. The microstrip to waveguide transition according to  claim 1 , wherein the repetitive structure is configured on a separate carrier assembled with the waveguide module. 
     
     
       5. The microstrip to waveguide transition according to  claim 1 , wherein the waveguide aperture is arranged to interface on the external side of the module with any of; a rectangular waveguide, an elliptical waveguide, or a circular waveguide. 
     
     
       6. The microstrip to waveguide transition according to  claim 1 , wherein the waveguide module is arranged to interface with a section of the PCB, comprising the patch antenna configured to face the passage into the waveguide aperture. 
     
     
       7. The microstrip to waveguide transition according to  claim 1 , wherein the waveguide module comprises one or more alignment holes configured to receive respective alignment taps soldered to the PCB. 
     
     
       8. The microstrip to waveguide transition according to  claim 1 , wherein the PCB comprises an integrated circuit. 
     
     
       9. The microstrip to waveguide transition according to  claim 1 , wherein the patch antenna comprises a plurality of antenna elements. 
     
     
       10. The microstrip to waveguide transition according to  claim 1 , wherein the waveguide module comprises a plurality of waveguide apertures, wherein each waveguide aperture is arranged to interface a different patch antenna. 
     
     
       11. The microstrip to waveguide transition according to  claim 1 , wherein the PCB further comprises at least one alignment tap soldered to the PCB at a location relative to the patch antenna and arranged to enter a respective alignment hole on the waveguide module. 
     
     
       12. A radio or radar transceiver comprising a microstrip to waveguide transition comprising:
 a waveguide module; and 
 a printed circuit board (PCB), 
 wherein the module is arranged to interface with the PCB, the PCB comprising a patch antenna and a ground plane, the module comprising a waveguide aperture and a repetitive structure, the waveguide aperture arranged extending through the module for attaching a waveguide to an external side of the waveguide module, the repetitive structure comprising a plurality of protruding metal or metallized elements arranged to surround the waveguide aperture on an internal side of the module and to define a passage into the waveguide aperture on the internal side, 
 wherein the repetitive structure is configured to attenuate electromagnetic signal propagation in a frequency band past the repetitive structure while allowing propagation via the passage, and 
 wherein the repetitive structure and ground plane constitute a gap waveguide structure, and 
 wherein the repetitive structure is arranged at a distance from the ground plane, where the distance is smaller than a quarter of an operation wavelength of the waveguide module.